If you eat less, you’ll lose weight. Sounds simple, right? But eating less is where it gets difficult. Your appetite doesn’t really know what it’s doing sometimes. While it can be hard to exercise willpower, it’s easier to limit what’s in front of you in the first place.

If you have doubts about whether people eat until the container is empty, consider the results of a research study done on soup consumption. Subjects ate from a bowl of soup that was rigged to refill itself from beneath the table in an imperceptible way. Participants ended up eating, on average, 73% more soup than those who ate from a normal bowl, but they didn’t believe they were any fuller or had eaten any more than the people eating from a normal bowl.

Take the bottomless-soup-bowl concept and apply it to a box of cookies or bag of chips. The container doesn’t provide you with any visual cue to how much you’ve eaten – so you end up eating a lot more than you realize.

Here’s how to eat less without exhausting your willpower: Use a dedicated snack bowl for all snacks, preferably a small one. Pick a bowl that will hold a single, measured serving of whatever snack you enjoy. If you pick a bowl large enough to allow you to share with others, you won’t know how much you’re eating. Choosing a smaller bowl for yourself is just as important. This was illustrated in a study of ice cream bowls and serving spoons. A group of nutrition experts eating from larger bowls were fooled into eating 31% more ice cream than other participants using smaller ones. And if nutrition experts can be influenced so easily, then we don’t have a chance.

Being a successful dieter or healthy eater is not just about what you know. It’s about what your body expects. Changing those expectations is one of the most challenging aspects of eating right. But you can change them without even realizing it by putting them in a new context with visual cues. And research also shows that if you change your behaviors first, you’ll tend to change your attitudes to fit them. So for starters, fit them into a bowl.